Size dependent reductive dissolution of ferrihydrite nanoparticles

COLL 387

R. Lee Penn, penn@chem.umn.edu1, Jasmine J. Erbs, erbs@chem.umn.edu1, Thelma S. Berquó, berqu013@umn.edu2, Benjamin Gilbert, BGilbert@lbl.gov3, and Subir Banerjee, banerjee@umn.edu4. (1) Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, (2) Institute for Rock Magnetism, University of Minnesota, 100 Union St. SE, Minneapolis, (3) Earth Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 90R1116, Berkeley, CA 94720, (4) Department of Geology and Geophysics, University of Minnesota, 310 Pillsbury Dr. SE, Minneapolis, MN 55455
Elucidating the fundamental chemical, structural, and physical properties can shed new and unexpected light on the behavior of both natural and synthetic nanoparticles. Iron oxides and oxyhydroxides commonly occur as nanoparticles in the 3-10 nm size range and strongly impact the biogeochemical cycle of iron and other species at and near the Earth's surface. We use a range of techniques in order to elucidate the link between chemical reactivity and the physical and structural properties of iron oxide nanoparticles. Ferrihydrite nanoparticles of varying size but similar aspect ratio were prepared by forced hydrolysis from ferric nitrate solutions, using matching solution chemistry for each sample. Overall, results demonstrate no size dependence in the relative reactivity, as quantified by the rate of reductive dissolution and confirmed by way of X-ray absorption spectroscopy, of the ferrihydrite nanoparticles. Solid-state characterization methods include X-ray diffraction, X-ray absorption, high-resolution transmission electron microscopy, and low temperature magnetism.
 

The Physical Chemistry of Environmental Interfaces
2:00 PM-6:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 225, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008